Abstracts

RATIONALE: We hypothesized that individuals dying of sudden unexplained death in epilepsy (SUDEP) would have abnormally enlarged hearts, increasing the risk of sudden cardiac death should the autonomic nervous system initiate a dysrhythmia. This study compares the mean heart mass of individuals who died of SUDEP to the mean heart mass of individuals with epilepsy who died suddenly due to some cause other than SUDEP. At the end of this activity participants should be able to discuss the relationship of SUDEP and heart mass and the diagnosis of SUDEP at autopsy in a medical examiner population.
METHODS: We conducted a retrospective review of 133 deaths investigated and autopsied by the Medical Examiner[ssquote]s office in decedents with a history of seizures. After reviewing each case, deaths were classified as SUDEP (n=57) or non-SUDEP (N=76, 8 deaths due to accident, 26 deaths unrelated to seizure, 42 deaths indeterminate between SUDEP and a potential anatomic cause such as heart disease). Age, history of hypertension, and history of alcoholism were examined as possible confounding factors. Expected heart mass was calculated using the decedent[ssquote]s body mass and published formulae.
RESULTS: We found no significant difference in the mean heart mass between the SUDEP (mean heart mass 358 grams) and non-SUDEP (mean heart mass 399 grams) groups when analyzing the unadjusted data from this study of decedents with a history of seizures who died suddenly. Analysis of unadjusted data showed a decreased frequency for dying of SUDEP in individuals with a heart mass at least 100 grams greater than expected based on body mass compared to those without an enlarged heart (odds ratio 0.30, 95% confidence interval 0.12-0.72). In other words, individuals with seizures who had an enlarged heart were 70% less likely to die of SUDEP than individuals with seizures who did not have an enlarged heart. The decrease in SUDEP was especially pronounced in individuals 40 or more years of age compared to those younger than 40 years (See Table, Classification 1). This decrease disappeared when cases where the cause of death was indeterminate between SUDEP and heart disease were reclassified from non-SUDEP to SUDEP (See Table, Classification 2).
CONCLUSIONS: Increased heart mass does not lead to an increased likelihood of dying of SUDEP. With increasing age the likelihood of finding a cause of death that competes with SUDEP increases, making SUDEP appear a phenomenon of the young. The inclusion of seizure deaths evaluated in a medical examiner office in studies of SUDEP would provide a more certain diagnosis in each given case. Moreover, the inclusion of cases from the medical examiner population would stem attrition in a study due to loss to follow-up.[table1]